Mixing drum



June 24, 1930. c. F.,BALL 1,766,582

MIXING DRUM Filed Dec. 27, 1926 Patented June 24, 193

9 F F! C E PATEN.

CHARLES E. BALL, OF MILWAUKEE, WISCONSIIT, ASSIGNOR T0 CHAIN BELT COMPANY, OF MILVJAUKEE, WISCONSIN, A CQRPOBATION OF WISCONSEN MIXING DRUM Application filed December 27, 1926.

My invention relates to the manufacture of metallic drums in which material that may be delivered thereto is mixed due to the rotation of the drums; and has for its object to improve such a drum and the manufac ture of the same by reducing the cost of manufacture and increasing the strength and otherwise improving the product. The invention has been made with especial reference to its embodiment in drums employed in the mixing of concrete, although it is not limited to that particular use.

In the accompanying drawings Figure l is a side view of a metallic drum constructed according to my invention, one end of the drum being represented in central longitudinal section.

Figure 2 is an end view of the drum, parts being broken away and represented in section.

Fig. 3 is a detail sectional view illustrating a feature of the invention not disclosed in the other views.

The central portion 2 of the drum is represented as being cylindrical in shape and formed of sheet metal of the desired thickness, which is bent to the desired shape and united at its edges as represented at 3. The edges are represented as being butt-welded together, although they may be lap-welded if desired, and the central portion of the drum may be other than of true cylindrical shape.

The ends of the drum are closed, or partially closed, by heads 4 which are preferably formed of sheet steel pressed into shape. The shaped heads 4i comprise, essentially, the closing ends 15 and cylindrical flanges 7 that are concentric with the end portions of the central part 2 of the drum. The cylindrical flanged portions of the heads are of such size, in diameter, as to fit closely the cylindrical ends of the body of the drum to which they are secured by any desired means.

The heads are represented as formed with central openings 5 through which the drum may be charged and discharged, and these openings are shown as being surrounded by annular plates 6 secured to the end walls of the heads.

The free edge of the cylindrical portion 7 Serial No. 157,330.

of the drum head is provided with an outturned flange preferably integral with the head and disposed at an angle, approximately of 102 or thereabouts, to the face of the part 7. The flanges 8 add greatly to the strength of the drum at its ends and where the heads are secured thereto, and being smooth-faced, serve also as side bearings for the supporting roller 12 upon which the drum rests. The heads a may be provided with tires or tread rings 9 secured to the external peripheries of the cylindrical portions 7 of the heads, if this be found desirable as shown in Fig. 3. lVheels or rollers 12 run upon the tires 9 when they are used.

The connections between the end wall portions 15 of the head and the cylindrical flanges 7 are in the form of reverse bends 10 which may be produced by the die presses employed in shaping the heads. I have found that the reverse bend connections, such as indicated at 10, add to the strength of the heads and reduce the danger of breakage where the parts 15 and 7 unite.

The out-turned flanges 8 are reinforced in the joints between such flanges and the ad jacent parts of the body 2 of the drum by a deposit of metal such as is employed in uniting the heads to the central body portion of the drum by welding or brazing processes such deposit being in the acute angles of the joints as indicated at 11. This reinforcement prevents the flanges 8 being bent inwardly or flattened against the outer face of the body 2 due to side thrust from, or against, the rollers 12. shafts 16 and are represented as consisting of hubs 13 to which are secured, as by rivets 17, the integral web and tread portions of the wheel which are represented as being formed of pressed steel. The outer faces of the Wheels, between the web and tread parts thereof, are curved as indicated at 14, and these curved faces are disposed toward the flanges 8. By arranging these flanges at an angle as indicated, and forming the wheels with curved faces 14 that run in engagement therewith, the wear and cutting of the flanges and of the wheels in use is very much reduced, as compared with an arrangement in These rollers are-supported upon which the side webs are at right angles to the tracks or faces on which the wheels run and the sides of the wheels that engage with such webs are at right angles to the treads of the wheels. The latter arrangement causes the webs to be cut attheir bases so that in use they are frequently sheared oil at these points.

There are several important practical advantages incident to making a concrete mixing drum with a head such as described, pan ticularly as compared with concrete mixing drums having cast iron heads, which has been the construction heretofore most commonlv used. In the first place the weight: of the rum is materially reduced, as much thinner metal may be employed than can be used with cast metal heads, and this is possible without reducing the strength of the drum. Indeed a drum with pressed steel heads such as described very much stronger and wears longer than a drum of like capacity having cast metal heads or ends. Another advantage is that the metal of the head that constitutes the track engaged by the supporting wheels or rollers 12 is of the same thickness or gage as the rest of the head, and yet when formed with the out-turned flange 8 it is of sufficient strength and stitfness to alone serve as a trackway for such supporting wheels. Heretot'ore when concrete mixing drums were provided with cast iron heads, it was necessary to make the tracks for the supporting wheels relatively very thick and heavy to insure the necessary strength. I am aware that concrete mixing machines have been made with pressed metal heads fonnedwith cylindrical portions that fit over the cylindrical ends of the drum, such cylindrical portions, however, bein r unflanged at their edges; but on using su mixing drum heads it was found necessary to mount upon the cylindrical portions thereof separate tiresthat are quite thick relative to the gage of the metal constituting the ends or heads of the drum, which tires might serve as the runways for the supporting wheels of the drum, such reinforcing tires being required to give the necessary strength to the runways. However. in practising my invention, it is found entirely unnecessary to use such supplementaltires, or to increase the thickness of the tread portions of the heads engaged by the supporting wheels, especially when the runways or treads are stiflened on the one side by the out-turned flanges such as 8, and on the other side by the connected web portion of the end or head, this being especially true when the connection between the tread 7 and the web part 15 is of re verse curve formation, as indicated at 10.

that I claim is:

A metallic mixii drum having a body portion with cylintli'ical ends, and sheet metal heads pressed into shape secured to the ends of the drum and formed with end walls and cylindrical parts adapted to be fitted and secured to the ends of the body portion of the drum and to serve as tracks to be engaged by wheels that support the drum, the free edges of the cylindrical parts of the heads being formed with out-turned smoothfaced flanges which are inclined to the face of the body of the drum and reinforced by deposit of metal in the acute angles of the joints between the said flanges and the ad jacent portions of the bodv of the drum.

CHARLES F. BALL. 

